The reading of the meter is carried out manually on-site and, on the basis of the data read, the power consumed is then billed to the household.
Many electricity providers also offer reduced rates that often cannot be controlled with a normal meter. These include, for example, minute electricity rates where a reduced rate is activated per minute depending on the load requirement of the public utility company as well as overnight rates, etc.
In order for an electricity provider to prepare a detailed bill, intelligent meters that count the rate currently used as well as the power consumed are required. Such intelligent meters are known as “smart meters” on the market.
In the case of conventional “smart meters”, the currently available rate offered by the electricity company is transmitted to the “smart meter” by means of an interface. Depending on the configuration, the “smart meter” then switches on or off one or several outputs to the consumer load at the current electricity rate.
The above-mentioned mode of operation of conventional “smart meters” has a number of disadvantages. The switching of some terminals is not without its complications. Many devices are dimensioned for operation without interruption, with the result that frequent switching on and off can lead to a fault or malfunction. A feed-in with a particular electricity from a particular rate can, therefore, only be inadequately performed.
Since conventional meters and “smart meters” are installed in the household by the electricity provider and the consumer loads are switched on and off via the information from the current electricity rate, the question arises as to whether the electricity provider even has the right to control devices in a household. Since the end customer is not the actual owner of the “smart meter”, it is thus unclear who owns the control rights to the end user's terminals.
Where the electricity provider has the possibility to control the terminals directly, the additional difficulty of technical implementation arises, as the control of each terminal belonging to an end customer undoubtedly requires a very high control effort which would be assumed by the electricity provider. This also raises the question of secure communication between the electricity provider and the “smart meter”. A sizeable risk exists that an unauthorized person may gain access to communication with the “smart meter” so as to switch terminals on or off.
WO 2006/017671 describes a smart meter system with the above-mentioned disadvantages. In said system, the connected consumer loads are connected by the electricity provider via the Internet. The difficulty of secure communication therefore arises coupled with the risk that an authorized person may gain access to the communication and the smart meter. By the same token, in the case of difficult devices, the user of the terminals cannot independently determine whether or not a device is to be switched on or off by means of rate adjustment. This solution also raises the issue of whether the public utility company is even allowed to own control rights over the end user.